As an example, Gray points to what he calls the "water vapor feedback loop." When scientists talk about global warming, they usually point to carbon dioxide as the most worrisome greenhouse gas. But that's just true in a roundabout way, Gray says.
Doubling the carbon dioxide in the atmosphere would raise the temperature only minimally in and of itself, he points out; predictions of large temperature increases of several degrees and more are based on the idea that the increased carbon dioxide will cause more water vapor--actually the major greenhouse gas--because of evaporation.
Only when computer modelers factor in water vapor as a gas that holds heat, rather than letting it escape into space, do they come up with the major warming scenarios. According to Gray, though, there's evidence that water vapor also shields the planet from sunlight, radiating that energy back into space. "It is my contention that there is no positive feedback," he says. The increase in water vapor, which holds in some heat but blocks out sunlight, effectively cancels itself out--which, he suggests, also cancels many of the global-warming predictions.
Gray has other criticisms of global warming's proponents. Modelers don't understand how the oceans work with the atmosphere, he says, and haven't been plugging the oceans' effects on cooling and heating into their equations accurately. As a result, much of what scientists are saying about global warming's impact on the number and ferocity of hurricanes is demonstrably wrong.
Although there were several particularly violent hurricanes in 1995, "there were many more hurricanes, of greater intensity, in the 1950s and 1960s," Gray points out. "They rarely note that because it doesn't fit their scenario. To the public it seems like hurricanes have gotten worse, but that's because there are more people and development in coastal areas."
As the discussion of global warming heats up, though, science often gets left behind. Gray says he's "outraged" that proponents of the theory claim their critics have been "paid off" by energy companies. Although some scientists have accepted energy-company money, those scientists were already questioning the global-warming research. "The money isn't much," he says, "$20,000 or something, which after taxes is what? $13,000. Who would sell their soul for that?
"I was approached by energy companies, but I didn't take the money. My God, I'm speaking for my own conscience. In the meantime, there's some $2 billion in government funding going to these other guys. They definitely have a vested interest in global warming being a big problem. That's how they make their living down at NCAR; they want global warming so they can get research money to study it."
After the Cold War ended and military spending on science dropped off, the scientific community needed to find "a new common enemy to support the scientific infrastructure--all those scientists and labs," Gray says. The National Science Foundation, which is NCAR's primary support, "needed to have a reason to ask for the public's money," he adds.
"And, of course, the media went along with it, because it needs a good disaster story to sell newspapers and magazines."
There are two dangers to accepting these global-warming stories as fact, Gray says. The first is that whatever treaty is worked out in Kyoto will affect industrialized nations the most, especially the United States. The U.S. produces the greatest amount of greenhouse gases, and therefore would have to make the greatest cuts to reach 1990 emissions levels, the number the IPCC panel supports. "Should we make commitments that could drastically affect our standard of living when we don't have to?" Gray asks. "It's doubtful the developing countries, which need to burn fossil fuels to catch up, will agree to any cuts...unless we're willing to subsidize them, which would lower our standard of living even further to bring them up."
The second danger concerns the integrity of science. "You can only cry wolf so often before people stop listening," Gray says.
The theory that man is the root of all evil is an old story, one that periodically resurfaces. "Centuries ago, in Spain, there was an earthquake, and the roof of a cathedral fell, killing hundreds of people," he says. "The local bishop said it was because so many of those people had sinned. It was man's fault. It's always our fault."
Challenging that view can have unappealing consequences. Colleagues at government agencies such as NOAA who have publicly questioned global-warming theories have been warned by superiors to keep their opinions to themselves, Gray says. And while he can't prove it, he believes that his recent difficulties in getting funding for his own research--even though it doesn't concern global warming--may be attributed to his own outspokenness.